<template>
  <div>
    <router-link v-show="showABS" tag="div" to="/" class="header-abs">
      <div class="iconfont header-back-icon">&#xe624;</div>
    </router-link>
    <div
      class="header-fixed"
      :style="opacityStyle"
      v-show="!showABS">
      景点详情
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
    </div>
  </div>
</template>

<script>
export default {
  name: 'detailHeader',
  data () {
    return {
      showABS: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {
          opacity
        }
        this.showABS = false
      } else {
        this.showABS = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
@import '~styles/varibles.styl';

.header-abs {
  z-index: 9;
  position: absolute;
  left: 0.2rem;
  top: 0.2rem;
  width: 0.8rem;
  height: 0.8rem;
  line-height: 0.8rem;
  border-radius: 0.4rem;
  text-align: center;
  background-color: rgba(0, 0, 0, 0.8);

  .header-back-icon {
    color: #fff;
    font-size: 0.4rem;
  }
}

.header-fixed {
  z-index: 9;
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  height: $headerHight;
  line-height: $headerHight;
  overflow: hidden;
  text-align: center;
  background: $bgcColor;
  color: #fff;
  font-size: 0.32rem;

  .header-fixed-back {
    position: absolute;
    left: 0;
    top: 0;
    width: 0.64rem;
    text-align: center;
    font-size: 0.4rem;
    color: #fff;
  }
}
</style>
